Scanning, in television, facsimile, and picture
transmission, the process of sequentially encoding the luminosity and optionally the
color of a picture or scene, line by line into an electronic
signal. It also refers to remotely reconstructing the picture or
scene on a display device.

Scanning, in telecommunications,
the process of rapidly tuning a
radio receiver through a predetermined range of frequencies to
select an active radio broadcast. Scanning may be performed
manually or automatically.

Scanning, in radar and
radio
direction-finding, the slewing of an antenna
or radiation
pattern for the purpose of probing in a different direction. In
radar, scanning may be mechanical, using a rotary microwave joint to feed the antenna, or electronic,
using a phased array
of radiators, the radiated pattern (beam) of which depends on the
relative phases of the signals fed to the individual radiators. In
civilian air traffic control radar, scanning usually implies
continuous rotation of the antenna or beam about a vertical axis.
In military radars, scanning may occur about other than a vertical
axis, and may not encompass a full 360°.

Scanning, in teaching reading, the technique for quickly
finding specific information in a text while ignoring its broader
meaning.

Scanning, in the semiconductor
electronics testing industry, to test the logic used in an
integrated circuit in a non-functional method by using a special
test mode. This mode generally changes the configuration of the
device being tested to look more similar to a large shift register.
Logical blocks are then tested by loading and unloading this
register. (See for instance JTAG Boundary Scan.)